The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory captions and links exemplifying features within the Earth system. The community is invited to contribute digital imagery, short captions and relevant links.

St. Cloud Roll Cloud

This nasty looking roll cloud is taking dead aim on the St. Cloud Middle School in St. Cloud, Florida. Since it seems to be separated from clouds above it, it's referred to as a "roll cloud." A shelf cloud is in essence the same as a roll cloud, but it's connected to an obvious parent cloud. The picture was taken at 5:52 p.m. on June 3, 2010, during the after school program I run. Fortunately, the storm wasn't as dangerous as it appeared; there was only minor wind damage and no injuries.

Old Glory snapping in the wind gives a strong clue that this cloud is not associated with a tornado. The wind is blowing in the direction that the storm is moving and not towards it, as would be the case with a tornado. However, because roll clouds are sometimes observed to rotate along their horizontal axis, they're indeed unnerving.